Thank you all for your kind words. I'm so so pleased that this thread (and others such as Biscuits') are inspiring people to sign up to donor registers. It's something I honestly hadn't given any thought to until my db got ill, so it's been a steep learning curve for me. Stem cell technology is going to get bigger and bigger, so it's vital that the message gets out there.
So- the process itself. Tbh, although I felt anxious at times, the reality always turned out to be ok! I worried about having the injections in my belly (fine,) I worried about the process itself - ok, there's a momentary scratch when the needles go in but then you don't feel a thing. And when else would you have an excuse to spend 6 hours sitting down with nothing to do but surf the Internet and watch catch up TV 
As a donor I had a nurse available to me all day, to open my sandwiches, pour me a drink, chat if I got bored, but ready to disappear off when I was occupied.
I was on a very high dose of the drugs which stimulate stem cell growth in the four days before donation, and even on this level I only got mild backache from fri- sun. It did get worse on Monday night, when a headache kicked in, BUT all of this is short lived and once the injections stop, you just get back to normal.
So, all in all it's less that a week out of my life which has the potential to give someone else YEARS of their life.
Reading the threads by biscuitsandbandages, dashingredhead, and posts from blondepip and many others makes me feel very grateful to have had this opportunity.
And just imagine if it was your child who needed a match... We would all move heaven and earth for it to happen.